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Deploy App Manually

Process
  1. Build images for our app
  2. Tag images so that they are named $REGISTRY/servicename
  3. Upload these images to a registry
  4. Create deployments using these images
  5. Expose (with a ClusterIP) these deployments so they can communicate with each other
  6. Expose (with a NodePort) the web UI so we can access it from outside

Deploying a self-hosted registry

Create the registry service: 

kubectl run registry --image=registry:2

Expose it on a NodePort: 

kubectl expose deploy/registry --port=5000 --type=NodePort

Connect to registry: 

MINIKUBE_IP=$(minikube ip)    # or 127.0.0.1 if main node

kubectl describe svc/registry
NODEPORT=$(kubectl get svc/registry -o json | jq .spec.ports[0].nodePort)

REGISTRY=$MINIKUBE_IP:$NODEPORT
curl $REGISTRY/v2/_catalog

Push image to registry: 

docker pull busybox
docker tag busybox $REGISTRY/busybox
docker push $REGISTRY/busybox

Building and pushing images

Build and push image: 

$ cat docker-compose.yml
version: "3"
services:
  rng:
    build: dockercoins/rng
    image: ${REGISTRY-127.0.0.1:5000}/rng:${TAG-latest}
    deploy:
      mode: global
  hasher:
    build: dockercoins/hasher
    image: ${REGISTRY-127.0.0.1:5000}/hasher:${TAG-latest}
  webui:
    build: dockercoins/webui
    image: ${REGISTRY-127.0.0.1:5000}/webui:${TAG-latest}
    ports:
      - "8000:80"
  redis:
    image: redis
  worker:
    build: dockercoins/worker
    image: ${REGISTRY-127.0.0.1:5000}/worker:${TAG-latest}
    deploy:
      replicas: 10


export REGISTRY
export TAG=v0.1
docker-compose build
docker-compose push

Deploy: 

kubectl run redis --image=redis
for SERVICE in hasher rng webui worker; do
    kubectl run $SERVICE --image=$REGISTRY/$SERVICE:$TAG
done

Exposing services internally

What to expose:

  • 3 deployments need to be reachable by others: hasher, redis, rng
  • worker doesn't need to be exposed
  • webui will be dealt with later

Expose deployments: 

kubectl expose deployment redis --port 6379
kubectl expose deployment rng --port 80
kubectl expose deployment hasher --port 80

Stream the worker's logs: 

kubectl logs deploy/worker --follow

Exposing services for external access

What to expose:

  • We want to access the Web UI
  • We will expose it with a NodePort (just like we did for the registry)

Create a NodePort service for the Web UI: 

kubectl expose deploy/webui --type=NodePort --port=80

Check that the port was allocated: 

kubectl get svc

Accessing the Web UI: